The______ breakdowns of the computer has caused serious delays in our work.

_________a sudden failure in operation. A: breakdown B: breakthrough C: breakthroughs D: breakdowns

Which of the following is not a disadvantage of air freight transportation? A: Very Costly B: Uncertain and Unreliable C: Slow Speed D: Breakdowns and Accidents

Nuclear power plants, ______ to some serious breakdowns, have become a center of controversy. A: having recently been subjected B: recently having been subjected C: have recently subjected D: recently have subjected